Disazo dyes and inks containing them

ABSTRACT

A compound comprising a disazo chromophore and an optionally substituted heterocyclic group linked together through a -SO2-NH- group, inks comprising these compounds, ink jet printer cartridges containing these inks and their use in ink jet printing.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a national phase application based onPCT/GB00/02995, filed Aug. 3, 2000, and which further claims priorityfrom British Application No. 9921929.7 filed Sep. 16, 1999. Theseapplications in their entirety are incorporated herein by reference.

This invention relates to compounds, to inks comprising these compounds,ink jet printer cartridges containing these inks and to their use in inkjet printing (“IJP”).

IJP is a non-impact printing technique in which droplets of ink areejected through a fine nozzle onto a substrate without bringing thenozzle into contact with the substrate.

There are many demanding performance requirements for dyes and inks usedin IJP. For example they desirably provide sharp, non-feathered imageshaving good water-fastness, light-fastness and optical density. The inksare often required to dry quickly when applied to a substrate to preventsmudging, but they should not form a crust over the tip of an ink jetnozzle because this will stop the printer from working. The inks shouldalso be stable to storage over time without decomposing or forming aprecipitate which could block the fine nozzle.

According to the present invention there is provided a compoundcomprising a disazo chromophore and an optionally substitutedheterocyclic group linked together through a —SO₂NH— group.

Preferably the nitrogen atom of the —SO₂NH— group is attached to theheterocyclic group by means of a single covalent bond. It is especiallypreferred that the compound is of Formula (1):

A—NH—SO₂—B—N═—D—N═N—E  Formula (1)

wherein:

A is an optionally substituted heterocylic group;

B and D are each independently optionally substituted phenylene ornaphthylene; and

E is optionally substituted naphthylene.

The optionally substituted heterocyclic group preferably comprises anoptionally substituted 5- or 6-membered heterocyclic ring, optionallyhaving a benzene ring fused thereon. Preferred heterocyclic ringscomprise 2, 3, 4 or 5 carbon atoms and 1, 2 or 3 atoms selected fromoxygen, nitrogen and sulphur.

Preferably the optionally substituted heterocyclic group is anoptionally substituted diazine, thiazole, benzthiazole, benzdiazine,isoxazole, benzisoxazole, thiadiazole, oxadiazole, isothiazole,triazole, benzisothiazole, pyridiazine, triazine, oxazole, thiophene,benzoxazole, pyrimidine or pyridine, preferably attached to the —NH—SO₂—group through a carbon atom adjacent to an oxygen, sulphur or nitrogenatom (e.g. at the 2-position). Particularly preferred are optionallysubstituted 2-thiazole, 2-benzthiazole and 2-diazine groups.

Preferably B is optionally substituted phenylene, more preferablyoptionally substituted 1,4-phenylene.

Preferably D is an optionally substituted 1,4-phenylene group, morepreferably a group of the formula:

wherein each:

W independently is H, optionally substituted alkyl, optionallysubstituted alkoxy, polyalkylene oxide, nitro, cyano, sulpho, halo,ureido, SO₂F, hydroxy, carboxy, ester, PO₄H₂, —NR¹R², —COR¹, —CONR¹R² or—SO₂NR¹R²;

X independently is O, NH or S;

R¹ and R² are each independently H or alkyl, preferably H or C₁₋₄-alkyl;and

R³ independently is H, optionally substituted alkyl or optionallysubstituted aryl.

Preferably each W independently is H, C₁₋₄-alkyl or C₁₋₄-alkoxy morepreferably H, methyl, ethyl, methoxy or ethoxy, especially H. Preferablyboth groups represented by W are H and X is O.

Preferably each R³ independently is optionally substituted C₁₋₄-alkyl oroptionally substituted phenyl more preferably C₁₋₄-alkyl orC₁₋₄-alkyl-OH, phenyl or phenyl carrying one or two substituentsselected from carboxy and sulpho.

Preferred optional substituents which may be present on the optionallysubstituted heterocyclic group, B, D or E are each independentlyselected from alkyl, more preferably C₁₋₄-alkyl; alkoxy, more preferablyC₁₋₄-alkoxy; polyalkylene oxide; nitro; cyano; sulpho; halo, especiallybromo, chloro or fluoro; ureido; SO₂F; hydroxy; carboxy; ester, morepreferably—CO₂(C₁₋₄-alkyl); PO₄H₂ and —NR¹R², —COR¹, —CONR¹R² and—SO₂NR¹R² wherein R¹ and R² are each independently H or alkyl,preferably H or C₁₋₄-alkyl.

When D is also optionally substituted naphthylene it preferably carriesone or more (preferably 1 to 4) substituents selected from hydroxy,amino, sulpho and carboxy.

Preferably E is optionally substituted naphthylene, more preferablycarrying one or more (preferably from 1 to 4) groups selected fromhydroxy, amino, sulpho and carboxy. More preferably E is naphthylenecarrying one hydroxy group, one amino group and 0, 1 or 2 sulpho groups.It is especially preferred that E is a 1-hydroxy-3-sulphonaphth-2-ylenegroup carrying an optionally substituted amino group at the 7-position;or a 1-hydroxy-5-sulphonaphth-2-ylene group carrying an optionallysubstituted amino group at the 8-position; or a1-hydroxy-3,6-disulphonaphth-2-ylene group carrying an optionallysubstituted amino group at the 8-position or a1-hydroxy-3,6-disulphonaphth-2-ylene group carrying an optionallysubstituted amino group at the 7-position.

Preferred optionally substituted amino groups are of the formula —NR⁴R⁵where R⁴ and R⁵ are independently selected from H, optionallysubstituted alkyl and optionally substituted phenyl. Preferably R⁴ andR⁵ are both H.

The compounds described hereinbefore are preferably soluble in water. Toachieve this solubility, the compounds preferably have 1, 2 or 3water-dispersing substituents. Preferred water-dispersing substituentsare polyalkylene oxides and more preferably sulpho and carboxy.

Preferred polyalkylene oxide groups which may be present on A, B, Dand/or E are poly(C₂₋₃-alkylene oxide) groups, more preferablypolyethylene glycol or polypropylene glycol, preferably having from 1 to20 glycol units and terminated with a hydroxy or C₁₋₄-alkoxy group.

Preferably A, B, D and E are selected from the definitions given abovesuch that the pKa of the linking —NH— group is from 8 to 3, morepreferably 7.5 to 4, especially 7 to 4.5. These preferences arise fromthe finding that compounds having such an —NH— group have a particularlygood combination of water-fastness and optical density when printed onpaper.

Any acid or basic groups on the compound, particularly carboxylic acidand sulphonic acid groups, are preferably in the form of a salt. Thusthe Formulae shown herein include the compounds in free acid and in saltform.

The compounds of the invention may be prepared by condensing a diazochromophore and an optionally substituted heterocyclic compound, whereone has a sulphonyl halide substituent and the other has an aminosubstituent. This condensation is preferably performed in the present ofbase to absorb hydrogen halide as it is generated during thecondensation.

The compound of Formula A—NH—SO₂—B—N═N—D—N═N—E may be prepared bydiazotising an amine of the formula A—NH—SO₂—B—N═N—D—NH₂ and couplingthe resultant diazonium salt with a compound of the formula H—E.

The compound of Formula A—NH—SO₂—B—N═N—D—NH₂ may be prepared bydiazotising an amine of the formula A—NH—SO₂—B—NH₂ and coupling theresultant diazonium salt with an amine of the formula H—D—NH₂. In somecases it may be necessary for the amino group to carry a protectinggroup which should be removed on completion of the reaction.

Many compounds of the formula A—NH—SO₂—B—NH₂ are commercially available.

Preferably they may be prepared by condensing an amine of formulaB—(NH₂)₂, in which one of the amino groups is protected, with a compoundof formula Cl—SO₂—NH—A followed by removal of the protecting group.

More preferably they may be prepared by condensing an amine of formulaA—NH₂ with a compound of formula Cl—SO₂—B—NH₂ carrying a protectinggroup on the amino group. of the Cl—SO₂—B—NH₂ compound, followed byremoval of the protecting group.

Diazotisation is preferably performed at a temperature below 6° C., morepreferably at a temperature in the range −10° C. to 5° C. Preferablydiazotsation is performed in water. The coupling reactions are performedat a pH below 7 for the monoazo intermediate and above pH 7 to formcompounds of Formula (1). Dilute mineral acid, e.g. HCl or H₂SO₄, may beused to achieve the desired acidic conditions.

In the above processes, A, B, D and E are as hereinbefore defined.

Preferred salts are alkali metal salts, especially lithium, sodium andpotassium salts, ammonium and substituted ammonium salts. Especiallypreferred salts are salts with ammonia and volatile amines. Thecompounds may be converted into a salt using known techniques. Forexample, an alkali metal salt of a compound may be converted into a saltwith ammonia or an amine by dissolving an alkali metal salt of thecompound in water, acidifying with a mineral acid and adjusting the pHof the solution to pH 9 to 9.5 with ammonia or the amine and removingthe alkali metal cations by dialysis or by treatment with an ionexchange resin.

The compounds described hereinbefore may exist in tautomeric forms otherthan those shown in this specification. These tautomers are includedwithin the scope of the present claims. The compounds are particularlyuseful as dyes, especially for ink jet printing compositions.

According to a second aspect of the present invention there is provideda composition comprising a compound according to the first aspect of theinvention, preferably of Formula (1), and a liquid medium.

Preferred compositions comprise:

(a) from 0.01 to 30 parts of a compound according to the first aspect ofthe invention, preferably of Formula (1); and

(b) from 70 to 99.99 parts of a liquid medium;

wherein all parts are by weight and the number of parts of (a)+(b)=100.

The number of parts of component (a) is preferably from 0.1 to 20, morepreferably from 0.5 to 15, and especially from 1 to 5 parts. The numberof parts of component (b) is preferably from 99.9 to 80, more preferablyfrom 99.5 to 85, especially from 99 to 95 parts.

Preferably component (a) is completely dissolved in component (b).Preferably component (a) has a solubility in component (b) at 20° C. ofat least 10%. This allows the preparation of liquid dye concentrateswhich may be used to prepare more dilute inks and reduces the chance ofthe dye precipitating if evaporation of the liquid medium occurs duringstorage.

Preferred liquid media include water, a mixture of water and an organicsolvent and an organic solvent free from water.

When the medium comprises a mixture of water and an organic solvent, theweight ratio of water to organic solvent is preferably from 99:1 to1:99, more preferably from 99:1 to 50:50 and especially from 95:5 to80:20.

It is preferred that the organic solvent present in the mixture of waterand organic solvent is a water-miscible organic solvent or a mixture ofsuch solvents. Preferred water-miscible organic solvents includeC₁₋₆-alkanols, preferably methanol, ethanol, n-propanol, isopropanol,n-butanol, sec-butanol, tert-butanol, n-pentanol, cyclopentanol andcyclohexanol; linear amides, preferably dimethylformamide ordimethylacetamide; ketones and ketone-alcohols, preferably acetone,methyl ether ketone, cyclohexanone and diacetone alcohol; water-miscibleethers, preferably tetrahydrofuran and dioxane; diols, preferably diolshaving from 2 to 12 carbon atoms, for example pentane-1,5-diol, ethyleneglycol, propylene glycol, butylene glycol, pentylene glycol, hexyleneglycol and thiodiglycol and oligo- and poly-alkyleneglycols, preferablydiethylene glycol, triethylene glycol, polyethylene glycol andpolypropylene glycol; triols, preferably glycerol and 1,2,6-hexanetriol;mono-C₁₋₄-alkyl ethers of diols, preferably mono-C₁₋₄-alkyl ethers ofdiols having 2 to 12 carbon atoms, especially 2-methoxyethanol,2-(2-methoxyethoxy)ethanol, 2-(2-ethoxyethoxy)-ethanol,2-[2-(2-methoxyethoxy)ethoxy]ethanol,2-[2-(2-ethoxyethoxy)-ethoxy]-ethanol and ethyleneglycol monoallylether;cyclic amides, preferably 2-pyrrolidone, N-methyl-2-pyrrolidone,N-ethyl-2-pyrrolidone, caprolactam and 1,3-dimethylimidazolidone; cyclicesters, preferably caprolactone; sulphoxides, preferably dimethylsulphoxide and sulpholane. Preferably the liquid medium comprises waterand 2 or more, especially from 2 to 8, water-soluble organic solvents.

Especially preferred water-soluble organic solvents are cyclic amides,especially 2-pyrrolidone, N-methyl-pyrrolidone and N-ethyl-pyrrolidone;diols, especially 1,5-pentane diol, ethyleneglycol, thiodiglycol,diethyleneglycol and triethyleneglycol; and mono- C₁₋₄-alkyl andC₁₋₄-alkyl ethers of diols, more preferably mono- C₁₋₄-alkyl ethers ofdiols having 2 to 12 carbon atoms, especially2-methoxy-2-ethoxy-2-ethoxyethanol.

Although not usually necessary, further colorants may be added to theink to modify the shade and performance properties. Examples of suchcolorants include C.I.Direct Yellow 86, 132, 142 and 173; C.I.DirectBlue 199, and 307; C.I.Food Black 2; C.I.Direct Black 168 and 195; C.I.Acid Yellow 23; and any of the dyes used in ink jet printers sold bySeiko Epson Corporation, Hewlett Packard Company, Canon Inc. & LexmarkInternational. Addition of such further dyes can increase overallsolubility leading to less kogation (nozzle blockage) for the resultantink.

Examples of further suitable liquid media comprising a mixture of waterand one or more organic solvents are described in U.S. Pat. Nos.4,963,189, 4,703,113, 4,626,284 and EP 4,251,50A.

When the liquid medium comprises an organic solvent free from water,(i.e. less than 1% water by weight) the solvent preferably has a boilingpoint of from 30° to 200° C., more preferably of from 40° to 150° C.,especially from 50 to 125° C. The organic solvent may bewater-immiscible, water-miscible or a mixture of such solvents.Preferred water-miscible organic solvents are any of the hereinbeforedescribed water-miscible organic solvents and mixtures thereof.Preferred water-immiscible solvents include, for example, aliphatichydrocarbons; esters, preferably ethyl acetate; chlorinatedhydrocarbons, preferably CH₂Cl₂; and ethers, preferably diethyl ether;and mixtures thereof.

When the liquid medium comprises a water-immiscible organic solvent,preferably a polar solvent is included because this enhances solubilityof the compound in the liquid medium. Examples of polar solvents includeC₁₋₄-alcohols. In view of the foregoing preferences it is especiallypreferred that where the liquid medium is an organic solvent free fromwater it comprises a ketone (especially methyl ethyl ketone) and/or analcohol (especially a C₁₋₄-alkanol, more especially ethanol orpropanol).

The organic solvent free from water may be a single organic solvent or amixture of two or more organic solvents. It is preferred that when themedium is an organic solvent free from water it is a mixture of 2 to 5different organic solvents. This allows a medium to be selected whichgives good control over the drying characteristics and storage stabilityof the ink.

Liquid media comprising an organic solvent free from water areparticularly useful where fast drying times are required andparticularly when printing onto hydrophobic and non-absorbentsubstrates, for example plastics, metal and glass.

The liquid media may also contain additional components conventionallyused in ink jet printing inks, for example viscosity and surface tensionmodifiers, corrosion inhibitors, biocides, kogation reducing additivesand surfactants which may be ionic or non-ionic.

It is preferred that a composition according to the second aspect of theinvention is an ink or liquid dye concentrate.

A third aspect of the invention provides a process for forming an imageon a substrate comprising applying an ink according to the second aspectof the invention to the substrate by means of an ink jet printer.

The ink used in this process is preferably a composition as defined inthe second aspect of the present invention.

The inks preferably have a total concentration of divalent metal ionsand trivalent metal ions below 1000, more preferably below 100,especially below 20, more especially below 10 parts per million byweight relative to the total weight of ink. Pure inks of this type maybe prepared by using high purity ingredients and/or by purifying the inkafter it has been prepared. Suitable purification techniques are wellknown, e.g. ultrafiltration, reverse osmosis, ion exchange andcombinations thereof.

The ink jet printer preferably applies the ink to the substrate in theform of droplets which are ejected through a small orifice onto thesubstrate. Preferred ink jet printers are piezoelectric ink jet printersand thermal ink jet printers. In thermal ink jet printers, programmedpulses of heat are applied to the ink in a reservoir by means of aresistor adjacent to the orifice, thereby causing the ink to be ejectedin the form of small droplets directed towards the substrate duringrelative movement between the substrate and the orifice. Inpiezoelectric ink jet printers the oscillation of a small crystal causesejection of the ink from the orifice.

The substrate is preferably paper, plastic, a textile, metal or glass,more preferably paper, an overhead projector slide or a textilematerial, especially paper.

Preferred papers are plain or treated papers which may have an acid,alkaline or neutral character.

A fourth aspect of the present invention provides a paper, an overheadprojector slide or a textile material printed with an ink according tothe second aspect of the invention, a compound according to the firstaspect of the invention or by means of a process of the third aspect ofthe invention.

A fifth aspect of the present invention provides an ink jet printercartridge comprising a chamber and an ink wherein the ink is in thechamber and the ink is according to the second aspect of the presentinvention.

A sixth aspect of the invention is a method for the colouration of asubstrate which comprises treating with a compound according to f thefirst aspect of the invention.

The invention is further illustrated by the following Examples in whichall parts and percentages are by weight unless otherwise stated.

EXAMPLE 1 Preparation of:

Sulfadiazine (19.6 parts), distilled water (500 parts) and concentratedhydrochloric acid (50 parts) were stirred at 0-5° C. Sodium nitrite(5.68 parts) dissolved in a minimum quantity of water was added overapproximately 3 minutes. The mixture was stirred at 0-5° C. for 1.5hours, then enough sulfamic acid was added to destroy any excess nitrousacid present and the mixture was stirred for a further 15 minutes. Thismixture was then added to a stirred mixture of 2,5-diethoxyaniline (14.9parts) and methylated spirits (740P, 400 parts) over approximately 15minutes with the co-addition of enough ice and saturated sodium acetatesolution to maintain the temperature 0-5° C. and the pH in the range of4-5. The mixture was then stirred at 0-5° C. for 1 hour, allowed to warmto room temperature and stirred over night at room temperature. Theproduct was filtered, washed twice with distilled water and dried atapproximately 70° C. overnight to yield 35 parts of monoazo intermediate88.9% strength as determined by C, H and N analysis.

The monoazo intermediate (7.1 parts) was dissolved in distilled water(500 parts) by the addition of the minimum amount of 47% caustic liquorwith stirring. Sodium nitrite (1.4 parts) was then added and thesolution was cooled to 0° C. This mixture was poured into a pre-cooled(0° C.) mixture of concentrated hydrochloric acid (14 parts) anddistilled water (11 parts) with vigorous stirring. The mixture wasstirred at 0-5° C. for 3 hours, then enough sulfamic acid was added todestroy any excess nitrous acid present and the mixture was stirred fora further 15 minutes. This mixture was then added to a stirred solutionof gamma acid (3.9 parts) and sodium carbonate (to pH 10) in water (200parts), over approximately 30 minutes with the co-addition of enough iceand 47% caustic liquor solution to maintain the temperature at 0-50° C.and the pH in the range of 9.5-10. The mixture was then stirred at 0-5°C. for 1 hour, allowed to warm to room temperature and stirred over theweekend at room temperature. The mixture was acidified to pH 3 by theslow addition of concentrated hydrochloric acid, the product wasfiltered, washed with dilute hydrochloric acid and triturated twice withacetone (500 parts) containing 880 ammonia (2 parts).

The crude sodium salt was then converted to the ammonium salt bydissolving the compound in an aqueous medium at approximately pH 10-11and slowly pouring this solution into an equal volume of vigorouslystirred 2N hydrochloric acid and filtering off the precipitate. Thisstep was then repeated.

The crude ammonium salt was dissolved in dilute aqueous ammonia atapproximately pH 10-11, filtered through a GF-A and GF-F glass fibrefilter and dialysed using ‘Visking tubing’. This solution was dried atapproximately 70° C. overnight to yield 3.6 parts of product which shownto have the correct structure by nmr and mass spectral analysis.

Inks were then prepared by dissolving the specified % by weight byweight of the compound in a stock solution of 9 parts water and 1 part1-methyl-2-pyrrolidone with the addition of concentrated ammonia to givea pH of 9-10. The inks were then filtered through a 0.45 micron membranefilter and printed onto Wiggins Conquer paper using HP 560 thermal IJprinter. The following results were obtained:

wt % Dye in ink OD* Run down (24 h)^(#) 2.5 1.443 7 4.0 1.496 4-5 *ODmeans optional density of the printed paper, as measured by an x-ritespectrometer. ^(#)Rundown was measured by printing the ink in parallelbands onto the paper, allowing the printed paper to dry for 24 hours,placing the printed paper at an angle of 45° and pouring 0.25 ml ofwater down the paper. The run down (a measure of wet-fastness) was givena score of 1 to 10, where 10 means no visible ink run (highwet-fastness).

EXAMPLE 2 Preparation of:

Example 1 was repeated except that 2,5-dimethoxyaniline was used inplace of 2,5-diethoxyaniline in the first coupling reaction and then 2Racid was used in place of gamma acid in the final coupling reaction.

Inks containing the title dye were prepared and printed onto WigginsConquer paper (as NH₄ ⁺ salt) as described in Example 1.

The following results were obtained:

wt % Dye in ink OD Run down (24 h) 2.5 1.424 5 4.0 1.495 4

EXAMPLE 3 Preparation of:

Example 1 was repeated except in place of 2,5-diethoxyaniline there wasused 2,5-dimethoxyaniline.

Inks containing the title dye were prepared and printed onto Xerox Acidpaper (as NH₄ ⁺ salt) as described in Example 1.

The following results were obtained:

wt % Dye in ink OD Run down (24 h) 2.5 1.424 7 3.5 1.454 6-7

EXAMPLE 4 Preparation of:

Example 2 was repeated except that p-carboxyphenyl gamma acid was usedin place of 2-R acid in the final coupling reaction.

Inks containing the title dye were prepared and printed onto WigginsConqueror (as NH₄ ⁺ salt) paper as described in Example 1.

The following results were obtained:

% Dye in ink OD Run down (24 h) 2.5 1.107 10

EXAMPLE 5 Preparation of:

Example 2 was repeated except that sulfathiazole replaced sulfadiazinein the first diazotisation reaction and then gamma acid was used inplace of 2-R acid in the final coupling reaction.

Inks containing the title dye were prepared and printed onto Xerox Acidpaper (as NH₄ ⁺ salt) as described in Example 1.

The following results were obtained:

% Dye in ink OD Run down (24 h) 2.5 1.226 9

EXAMPLE 6 Preparation of:

Example 2 was repeated except that sulfathiazole replaced sulfadiazinein the first diazotisation reaction and then p-carboxyphenyl gamma acidwas used in place of 2-R acid in the final coupling reaction.

Inks containing the title dye were prepared and printed onto Xerox Acidpaper (as NH₄ ⁺ salt) as described in Example 1.

The following results were obtained:

% Dye in ink OD Run down (24 h) 2.5 1.015 10

EXAMPLE 7 Preparation of:

Example 2 was repeated except that sulfathiazole replaced sulfadiazinein the first diazotisation reaction and then ethylpiperazino gamma acidwas used in place of 2-R acid in the final coupling reaction.Ethylpiperazino gamma acid was prepared as described in Example 1, stage2, of WO 9732931.

Inks containing the title dye were prepared and printed onto Xeroxalkali paper as described in Example 1.

The following results were obtained:

% Dye in ink OD Run down (24 h) 2.5 0.995 10

EXAMPLE 8 Preparation of:

Example 1 was repeated except cresidine was used in place of2,5-diethoxyaniline in the first coupling reaction.

Inks containing the title dye were prepared as described in Example 1except that a mixture of glycerol (7.5%), thiodiglycol (7.5%), urea(7.5%) and sulfonyl 465 (1%) was used in place of N-methyl-2-pyrolidoneand the resultant ink was printed onto Xerox Acid (as NH₄ ⁺ salt) paperusing a Canon BJC-2000 printer.

The following results were obtained:

% Dye in ink OD Run down (24 h) 3.5 1.034 9.5

Further Inks

The inks described in Tables I and II may be prepared wherein the Dyedescribed in the first column is the Dye made in the above example ofthe same number. Numbers quoted in the second column onwards refer tothe number of parts of the relevant ingredient and all parts are byweight. The inks may be applied to paper by thermal or piezo ink jetprinting.

The following abbreviations are used in Table I and II:

PG=propylene glycol

DEG=diethylene glycol

NMP=N-methyl pyrolidone

DMK=dimethylketone

IPA=isopropanol

MEOH=methanol

2P=2-pyrolidone

MIBK=methylisobutyl ketone

P12=propane-1,2-diol

BDL=butane-2,3-diol

CET=cetyl ammonium bromide

PHO=Na₂HPO₄ and

TBT=tertiary butanol

TDG=thiodiglycol

TABLE I Dye Na Example Content Water PG DEG NMP DMK NaOH Stearate IPAMEOH 2P MIBK 1 2.0 80 5 6 4 5 2 3.0 90 5 5 0.2 3 10.0 85 3 3 3 5 1 4 2.191 8 1 5 3.1 86 5 0.2 4 5 6 1.1 81 9 0.5 0.5 9 7 2.5 60 4 15 3 3 6 10 54 8 5 65 20 10 3 2.4 75 5 4 5 6 5 6 4.1 80 3 5 2 10 0.3 1 3.2 65 5 4 6 54 6 5 3 5.1 96 4 1 10.8 90 5 5 2 10.0 80 2 6 2 5 1 4 1 1.8 80 5 15 1 2.684 11 5 1 3.3 80 2 10 2 6 4 12.0 90 7 0.3 3 1 5.4 69 2 20 2 1 3 3 5 6.091 4 5

TABLE II Dye Example Content Water PG DEG NMP CET TBT TDG BDL PHO 2P PI21 3.0 80 15 0.2 5 2 9.0 90 5 1.2 5 3 1.5 85 5 5 0.15 5.0 0.2 4 2.5 90 64 0.12 5 3.1 82 4 8 0.3 6 6 0.9 85 10 5 0.2 7 8.0 90 5 5 0.3 8 4.0 70 104 1 4 11 2 2.2 75 4 10 3 2 6 1 10.0 91 6 3 3 9.0 76 9 7 3.0 0.95 5 6 5.078 5 11 6 1 5.4 86 7 7 8 2.1 70 5 5 5 0.1 0.2 0.1 5 0.1 5 7 2.0 90 10 12 88 10 4 5 78 5 12 5 1 8 70 2 8 15 5 4 10 80 8 12 5 10 80 10

What is claimed is:
 1. A compound comprising a disazo chromophore and anoptionally substituted heterocyclic group linked together through a—SO₂—NH— group wherein the nitrogen atom of the —SO₂—NH— group isattached to the heterocyclic group by means of a single covalent bond,said compound being represented be the following Formula (1):A—NH—SO₂—B—N═N—D—N═N—E  Formula (1) wherein: A is an optionallysubstituted heterocylic group; B and D are each independently optionallysubstituted phenylene or naphthylene; and E is optionally substitutednaphthylene.
 2. A compound according to claim 1 wherein the optionallysubstituted heterocyclic group A comprises an optionally substituted 5-or 6-membered heterocylic ring, optionally having a benzene ring fusedthereon.
 3. A compound according to claim 1 wherein the optionallysubstituted heterocyclic group A comprises a heterocyclic ringcomprising 2, 3, 4 or 5 carbon atoms and 1, 2 or 3 atoms selected fromoxygen, nitrogen and sulphur.
 4. A compound according to claim 1 whereinB is optionally substituted phenylene.
 5. A compound according to claim1 wherein B is optionally substituted 1,4-phenylene.
 6. A compoundaccording to claim 1 wherein D is optionally substituted phenylene.
 7. Acompound according to claim 1 wherein D is of the formula:

wherein each: W independently is H, optionally substituted alkyl,optionally substituted alkoxy, polyalkylene oxide, nitro, cyano, sulpho,halo, ureido, SO₂F, hydroxy, carboxy, ester, PO₄H₂, —NR¹R², —COR¹,—CONR¹R² or —SO₂NR¹R², wherein R¹ and R² are each independently H oralkyl; X independently is O, NH or S; and R³ independently is H oroptionally substituted alkyl or optionally substituted aryl.
 8. Acompound according to claim 1 wherein D is naphthylene crying one ormore substituents selected from the group consisting of hydroxy, amino,sulpho and carboxy.
 9. A compound according to claim 1 wherein E isnaphthylene carrying one or more substituents selected from the groupconsisting of hydroxy, amino, sulpho and carboxy.
 10. A compoundaccording to claim 1 wherein E is a 1-hydroxy-3-sulphonaphth-2-ylenegroup carrying an optionally substituted amino group at the 7-position;or a 1-hydroxy-5-sulphonaphth-2-ylene group carrying an optionallysubstituted amino group at the 8-position; or a1-hydroxy-3,6-disulphonaphth-2-ylene group carrying an optionallysubstituted amino group at the 8-position or a1-hydroxy-3,6-disulphonaphth-2-ylene group carrying an optionallysubstituted amino group at the 7-position.
 11. A compound according toclaim 1 wherein the pKa of the —NH— group is from 8 to
 3. 12. Acomposition comprising a compound according to claim 1 and a liquidmedium.
 13. A composition which is an ink or liquid dye concentrate,comprising a compound comprising a disazo chromophore and an optionallysubstituted heterocyclic group linked together through a —SO₂—NH— groupwherein the nitrogen atom of the —SO₂—NH— group is attached to theheterocyclic group by means of a single covalent bond.
 14. A process forforming an image on a substrate comprising applying an ink according toclaim 13 thereto by means of an ink jet printer.
 15. A paper, anoverhead projector slide or a textile material printed with an inkaccording to claim
 13. 16. An ink jet printer cartridge comprising achamber and an ink wherein the ink is in the chamber and the ink is asdescribed in claim
 13. 17. A paper, an overhead projector slide or atextile material printed with an ink containing a compound comprising adisazo chromophore and an optionally substituted heterocyclic grouplinked together through a —SO₂—NH— group wherein the nitrogen atom ofthe —SO₂—NH— group is attached to the heterocyclic group by means of asingle covalent bond.
 18. A paper, an overhead projector slide or atextile material printed by means of a process according to claim 14.19. An ink or liquid dye composition according to claim 13, wherein thecompound is a compound of Formula (I): A—NH—SO₂—B—N═N—D—N═N—E  Formula(1) wherein: A is an optionally substituted heterocylic group; B and Dare each independently optionally substituted phenylene or naphthylene;and E is optionally substituted naphthylene.
 20. A process for formingan image on a substrate comprising applying an ink according to claim 19thereto by means of an ink jet printer.
 21. A paper, an overheadprojector slide or a textile material printed with an ink according toclaim
 19. 22. An ink jet printer cartridge comprising a chamber and anink wherein the ink is in the chamber and the ink is as described inclaim
 19. 23. A paper, an overhead projector slide or a textile materialprinted with an ink containing a compound according to claim
 1. 24. Apaper, an overhead projector slide or a textile material printed bymeans of a process according to claim 20.